I get the impression that we can add or remove tools to the right click context menu to suit our own styles and needs.
ie. I would love to have some simple often-used commands like Trim, Extend, Mirror, and Parallel up there with Move, Rotate etc.
Is this so?
And, If so, Will someone please explain or demonstrate exactly how this is done as I have been thus far unable to achieve it.

Yes. I was beginning to wonder if that was true. My bad .. I misunderstood.
I am aware of "Customize". (How cool to edit your own preference of tool icons..!)
I just assumed Context menu meant Right click options.
Thank you for the clarification.

May I then make a suggestion to this effect for future implementation .. Perhaps